The present invention relates to a DC backup power supply system having a non-service interruption function, and a disk array provided with the same.
With communication/information equipment such as a disk array, AC is received from a commercial AC power source to be thereby converted into DC by an AC/DC converter, whereupon the DC is further adjusted so as to be at various voltages required by respective circuits in the disk array by DC/DC converters before supplying power to the respective circuits (loads). As an uninterrupted power supply (UPS) in this field, there is, for example, a technology disclosed in Patent Document 1. In the case of the technology, a backup power supply is connected to DC paths between a converter and respective loads inside equipment, and power from an AC power source is converted into DC power when the converter is in normal operation, thereby supplying the DC power to the respective loads while charging a battery. At the time of a power outage, DC power is supplied from the backup power supply to a plurality of loads through the intermediary of switchover means for selectively switching over between the plurality of the loads before connection. Then, when there is a drop in the amount of the actual capacity that remains in the backup power supply, power supply to the respective loads is sequentially stopped in decreasing order of power consumption, thereby implementing operation of main specific loads for long-duration.
Further, in Patent Document 2, there is disclosed a backup power supply of an intrusion monitoring system, having a switch for switching over between a commercial power source and the backup power supply at the time of a power outage, and for limiting operation time of a warning speaker, thereby causing a monitoring function of the backup power supply to be maintained for long duration thereafter.    [Patent Document 1] JP-A No. 156942/2000 (in whole)    [Patent Document 2] JP-A No. 23054/2001 (Paragraph Nos. 26 to 30, FIGS. 4 to 6, and others)